U.S. patent application number 15/371705 was filed with the patent office on 2017-06-15 for guide-roll arrangement for guiding relative movement of mast segments of a lift-truck and a lift-truck comprising a guide-roll arrangement.
The applicant listed for this patent is Toyota Material Handling Manufacturing Sweden AB. Invention is credited to Mikael Nordenhem.
Application Number | 20170166425 15/371705 |
Document ID | / |
Family ID | 57286376 |
Filed Date | 2017-06-15 |
United States Patent
Application |
20170166425 |
Kind Code |
A1 |
Nordenhem; Mikael |
June 15, 2017 |
Guide-Roll Arrangement for Guiding Relative Movement of Mast
Segments of a Lift-Truck and a Lift-Truck Comprising a Guide-Roll
Arrangement
Abstract
A guide-roll arrangement for guiding movement of a second mast
segment relative a first mast segment of a lift-truck, comprising a
roll pin having opposing first and second ends, wherein the first
end comprises a recess, and a roll supported on the roll pin; and a
sliding element arranged in the recess, said sliding element
comprising opposing contact and sliding surfaces, wherein a support
piece is arranged in the recess and comprising a contact surface
for supporting the sliding element, wherein the contact surface of
the sliding element is supported on the contact surface of the
support piece and wherein one of the contact surfaces of the
support piece and the sliding element is concave and the other is
convex.
Inventors: |
Nordenhem; Mikael;
(Vikingstad, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Toyota Material Handling Manufacturing Sweden AB |
Mjolby |
|
SE |
|
|
Family ID: |
57286376 |
Appl. No.: |
15/371705 |
Filed: |
December 7, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B66F 9/08 20130101; F16C
29/045 20130101; F16C 29/04 20130101; B66F 9/07 20130101 |
International
Class: |
B66F 9/08 20060101
B66F009/08; B66F 9/07 20060101 B66F009/07 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 2015 |
SE |
1551613-1 |
Claims
1. A guide-roll arrangement for guiding movement of a second mast
segment of a lift-truck relative a first mast segment of said
lift-truck, wherein said first and second mast segments
respectively comprises an elongated track having a bottom and
opposing sidewalls, wherein the guide-roll arrangement comprises: a
roll pin having opposing first and second ends, wherein the first
end comprises a recess; and a roll supported on the roll pin; and a
sliding element arranged in the recess, said sliding element
comprising opposing contact and sliding surfaces; wherein the roll
is configured to engage one of the opposing sidewalls of the track
and the sliding surface of the sliding element is configured to
slidable engage the bottom of the track; and wherein the second end
of the roll pin is configured to be attached to one of the first
and second mast segments, and a support piece arranged in the
recess of the roll pin and comprising a contact surface for
supporting the sliding element, wherein the contact surface of the
sliding element is supported on the contact surface of the support
piece and wherein one of the contact surfaces of the support piece
and the sliding element is concave and the other of the contact
surfaces of the support piece and the sliding element is
convex.
2. The guide-roll arrangement according to claim 1, wherein the
sliding element and the support piece have circular cross-section
and the contact surfaces of the sliding element and the support
piece are spherical.
3. The guide-roll arrangement according to claim 1, wherein the
contact surface of the sliding element is a rounded end of the
sliding element and the contact surface of the support piece is a
depression in the support piece.
4. The guide-roll arrangement according to claim 1, wherein the
contact surfaces of the sliding element and the support piece have
corresponding diameter.
5. The guide-roll arrangement according to claim 1, wherein the
recess comprises an annular distance element for supporting the
sliding element in radial direction (Y) of the recess.
6. The guide-roll arrangement according to claim 5, wherein the
annular distance element comprises elastic material and is
configured to allow radial movement of the sliding element in the
recess.
7. The guide-roll arrangement according to claim 1, further
comprising a threaded adjustment element extending through a
threaded bore from the second end of the roll pin to the recess,
wherein the threaded adjustment element is connected to the support
piece to move the support piece in axial direction (X) of the roll
pin.
8. A lift-truck comprising an extendable mast having at least a
first and a second mast segment wherein said second mast segment is
movable relative said first mast segment, wherein said first and
second mast segment respectively comprises an elongated track
having a bottom and opposing sidewalls, and the lift-truck
comprises at least a first guide-roll arrangement according to
claim 1.
9. The lift-truck according to claim 8 wherein at least a first and
a second guide-roll arrangement are attached to the second mast
segment and wherein at least a third and a fourth guide-roll
arrangement are attached to the first mast segment.
10. The lift-truck according to claim 8, comprising a third mast
segment which is movable relative said second mast segment.
11. The lift-truck according to claim 10 wherein at least a fifth
and a sixth guide-roll arrangement are attached to the second mast
segment and wherein at least a seventh and an eight guide-roll
arrangement are attached to the third mast segment.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Swedish
Patent Application No. 1551613-1 filed Dec. 9, 2015, the contents
of which is hereby incorporated by reference as if set forth in its
entirety herein.
TECHNICAL FIELD
[0002] The present disclosure relates to a guide-roll arrangement
for guiding movement of a second mast segment relative a first mast
segment of a lift-truck. The present disclosure also relates to a
lift-truck comprising a guide-roll arrangement.
BACKGROUND ART
[0003] Lift-trucks comprise various parts that are movable axially
relative each other or with respect to the chassis of the truck.
For example, an extendable mast of the lift-truck may comprise two
or more mast segments which are slidable arranged in each other so
that the segments may be moved apart and extended telescopically.
The lift-truck may further comprise a movable carrier which
supports components of the lift-truck. For example the lift-truck
may comprise a carrier for supporting load engagement means such as
forks or clamping means. The carrier is arranged to be moved along
a mast segment of the lifting mast of the lift-truck. A lift-truck
comprising load engagement means in the form of a lifting fork is
typically denominated a forklift-truck. In so-called reach
lift-trucks, the mast of the lift-truck is attached to a carrier,
i.e. a mast carriage, which is movable along an element of the
lift-truck, for example along the support legs of the lift-truck or
along a U-beam in the support legs.
[0004] Typically, guide-rolls are provided to ensure a smooth axial
movement of one part relative the other part. For example, guide
rolls may be arranged between a fixed mast segment and a movable
mast segment of an extendable mast. The hub of a guide-roll is
thereby attached to one of the mast segments whereby the roll
itself engages one of the opposing sidewalls of a track which
extends along the other mast segment. A carrier for load engagement
means may be provided with guide rolls which run in tracks on the
inner mast segment of the lift-truck.
[0005] The guide-roll stabilizes the relative movement of the parts
in the intended axial direction of movement since the surface of
the guide roll is in contact with one of the opposing sidewalls of
the track. However, to ensure a completely smooth relative movement
between the parts it may often be necessary to prevent movement
between the movable parts in directions which are non-parallel to
the intended axial direction of movement. For this purpose, the
guide roll may comprise a sliding block which protrudes from the
hub of the guide roll and is arranged to slide along the bottom of
the track. Examples of guide-rolls with sliding blocks for
lift-trucks are disclosed in the documents WO2006024522, U.S. Pat.
No. 4,234,057, U.S. Pat. No. 4,914,712, SE460116 and U.S. Pat. No.
4,375,247.
[0006] However, occasionally the tracks in which the guide-rolls
run are not sufficiently straight, for example the bottom of the
flanged track may be uneven. It is also possible that external
forces may displace one of the parts in relation to the other. This
may cause the sliding block of a conventional guide-roll to be
pressed with an uneven pressure onto the bottom of the track. This
is turn may result in uneven and sometimes excessive wear of the
sliding block.
[0007] Thus, it is an object of the present disclosure to provide
an improved guide-roll arrangement for guiding movement of second
mast segment relative a first mast segment of a lift-truck, whereby
said guide-roll arrangement solves or at least mitigates at least
one of the problems of the prior-art. In particular, it is an
object of the present disclosure to provide a guide-roll
arrangement which has long service life. It is also an object of
the present disclosure to provide a lift-truck comprising an
improved guide-roll arrangement.
SUMMARY OF THE INVENTION
[0008] According to a first aspect of the present disclosure at
least one of the aforementioned objects is met by a guide-roll
arrangement 50 for guiding movement of a second mast segment 112,
113 of a lift-truck 100 relative a first mast segment 111, 112, 113
of said lift-truck 100, wherein said first and second mast segments
111, 112, 113 comprises an elongated track 114 having a bottom 115
and opposing sidewalls 116, 117, wherein the guide-roll arrangement
50 comprises: [0009] a roll pin 10 having opposing first and second
ends 11, 12, wherein the first end 11 comprises a recess 13; and a
roll 20 supported on the roll pin 10; and a sliding element 30
arranged in the recess 13, said sliding element 30 comprising
opposing contact and sliding surfaces 31, 32; [0010] wherein the
roll 20 is configured to engage one of the opposing sidewalls 116,
117 of the track 114 and the sliding surface 32 of the sliding
element 30 is configured to slidable engage the bottom 115 of the
track 114; and [0011] wherein the second end 12 of the roll pin 10
is configured to be attached to one of the first and second mast
segments 111, 112, 113, and a support piece 40 arranged in the
recess 13 of the roll pin 10 and comprising a contact surface 41
for supporting the sliding element 30, wherein the contact surface
31 of the sliding element 30 is supported on the contact surface 41
of the support piece 40 and wherein one of the contact surfaces 31,
41 of the support piece 40 and the sliding element 30 is concave
and the other of the contact surfaces 31, 41 of the support piece
40 and the sliding element 30 is convex.
[0012] In the guide-roll arrangement according to the present
disclosure, the mating concave/convex contact surfaces of the
sliding element and the support piece allows the sliding element to
move freely in all directions and by any suitable angle in the
guide roll arrangement. The sliding surface of the sliding block
may thereby remain with constant pressure in contact with the
bottom of the track regardless of any angular displacement between
the two relatively movable mast segments of the lift-truck. In
operation, this reduces considerably the wear of the sliding
element which in turn results in less downtime of the lift-truck
due to maintenance and reduced operational cost for the
lift-truck.
[0013] A second aspect of the present disclosure is a lift-truck
100 comprising an extendable mast 110 having at least a first and a
second mast segment 111, 112 wherein said second mast segment 112
is movable relative said first mast segment 111, wherein said first
and second mast segment 111, 112, 113 respectively comprises an
elongated track 114 having a bottom 115 and opposing sidewalls 116,
117, and the lift-truck 100 comprises at least a first guide-roll
arrangement 50 according to the present disclosure.
[0014] Further alternatives and advantages of the present
disclosure are disclosed in the appended claims and the following
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1: A schematic side view drawing of a lift-truck
according to the present disclosure.
[0016] FIG. 2: A schematic front view drawing of the mast of a
lift-truck according to the present disclosure.
[0017] FIGS. 3a, 3b, 3c: Schematic cross-sectional drawings of the
mast of a lift-truck according to the present disclosure.
[0018] FIG. 4: A schematic side view drawing showing a guide-roll
arrangement according to the present disclosure.
[0019] FIGS. 5a, 5b: A schematic drawing showing the functional
principle of the guide-roll arrangement according to the present
disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0020] The guide-roll arrangement according to the present
disclosure will now be described more fully hereinafter. The
embodiments described hereinafter are provided by way of example so
that this disclosure will be thorough and complete, and will fully
convey the scope of the present disclosure to those persons skilled
in the art. Same reference numbers refer to same elements
throughout the description.
[0021] FIG. 1 shows schematically a lift-truck 100 according to the
present disclosure in side view. The lift-truck of FIG. 1 is a
reach lift-truck. However, other lift-trucks are also contemplated
with the scope of the present disclosure, for example stacker
lift-trucks and order picker lift-trucks.
[0022] The lift-truck 100 comprises a mainframe 105 which in its
forward portion extends into two forward support legs 101 carrying
support wheels 102. A drive wheel 103 is arranged in the rear of
the mainframe 105. In FIG. 1 only one of the support legs and the
support wheels are shown. The mainframe 105 supports a chassis 106
in which an electrical drive motor for propelling the drive wheel
and a hydraulic system for providing hydraulic power to movable
parts on the lift-truck is accommodated (the motor and the
hydraulic system are not shown in FIG. 1). The chassis 106 further
comprises a driver's compartment 104, comprising a seat and
controls for driving and controlling the lift-truck (not shown in
FIG. 1). The lift-truck 100 further comprises an extendable lifting
mast 110. The lifting mast 110 shown in FIG. 1 comprises three mast
segments: a first outer mast segment 111, a second middle mast
segment 112 and a third inner mast segment 113.
[0023] FIG. 2 shows a front view of the lifting mast 110. Each mast
segment thereby comprises two vertical uprights of e.g. I-beam
shape that are interconnected by crossbars (not shown). The outer
mast segment 111 is supported on the main frame 105 of the
lift-truck. The middle mast segment 112 is arranged within the
outer mast segment 111 and is arranged movable relative the outer
mast segment 111. The inner mast segment 113 is arranged within the
middle mast segment 112 and is arranged movable relative the middle
mast segment 112. Actuation of the respective movable mast segments
112, 113 is performed by hydraulic lifting cylinders and lifting
chains (not shown). The lifting mast 110 may also comprise further
mast segments, such a forth and a fifth mast segment. It is also
possible that the lifting mast 110 only comprises a first and a
second mast segment.
[0024] Returning to FIG. 1. The lift-truck further comprises a load
carriage 118, which is arranged movable in the inner mast segment
113 such that the load carriage 118 may be moved relative the inner
mast segment 113 in vertical direction upwards or downwards.
Different load engaging means may be attached to the load carriage
118, for example a lifting fork or clamping means such as gripping
arms that are arranged movable towards each other for gripping and
holding a load. In the lift-truck of FIG. 1 a lifting fork is
attached to the load carriage 118.
[0025] As described, the lift-truck 100 of FIG. 1 is a reach
lift-truck, i.e. a lift-truck having the capability of moving the
lifting mast 110 parallel to the main frame 105 of the lift-truck.
The outer mast segment 111 is thereby supported on a lifting mast
carriage 130, which is arranged movable in the support legs 101 of
the lift-truck such that the lifting mast may be moved relative the
support legs 101 back and forth in direction from the rear of the
lift-truck towards the support wheels 102. However, the lifting
mast 110 may also be directly supported on the main frame 105 of
the lift-truck, i.e. the outer mast segment 111 of the lifting mast
110 may be firmly fixed to the mainframe 105 of the lift-truck.
[0026] The lift-truck further comprises guide-roll arrangements 50
that are arranged to guide movement of the various parts of the
lift-truck described above. Thus guide roll-arrangements 50 are
arranged to guide movement of the second, middle, mast segment 112
relative the first, outer, mast segment 111. Guide-roll
arrangements 50 are further arranged to guide movement of the
third, inner, mast segment 113 relative the second, middle, mast
segment 112 and vice versa. Guide-roll arrangements 50 may further
be arranged to guide movement of the load carriage 118 relative the
inner mast segment 113. Guide-roll arrangements 50 may also be
arranged to guide movement of the lifting mast carriage 130
relative the support legs 101 of the lift-truck.
[0027] The guide-roll arrangement 50 according to the present
disclosure is hereinafter described in detail with reference to the
movable mast segments 111, 112, 113 of the lifting mast 110.
[0028] FIG. 3a is a view from above of the lifting mast 110 of FIG.
2 and shows the mast segments 111, 112 and 113 of the lifting mast
110. The outer mast segment 111 comprises two uprights 111.1 111.2.
The middle mast segment 112 comprises two uprights 112.1, 112.2 and
the inner mast segment 113 comprises two uprights 113.1, 113.2. A
first and a second guide-roll arrangement 50 are attached to the
respective uprights 111.1 and 111.2 of the outer mast segment 111
and a third and a fourth guide-roll arrangement 50 are attached to
a respective upright 112.1, 112.2 of the middle mast segment
112.
[0029] FIG. 3b is an enlarged cross-sectional view of the right
side of the lifting mast of FIG. 3a and shows the right uprights
111.1, 112.1 and 113.1 of the mast segments 111, 112, 113 in
cross-section. It is appreciated that the left side uprights 111.2,
112.2, 113.2 are identical to the right side uprights 111.1, 112.1,
113.1. Each of the uprights of the respective mast segments 111,
112, 113 comprises at least one elongated track 114 having a bottom
115 and two opposing sidewalls 116, 117. The track 114 extends
along the respective upright of each mast segment in axial
direction between the ends of the mast segment. The elongated track
114 may thereby extend along the entire upright or along a portion
thereof. Depending on the mast configuration, an upright may
comprise one track 114 or two tracks 114. Thus, a first track 114
may extend along a first side of an upright and a second track 114
may extend along a second side of the same upright.
[0030] A guide-roll arrangement 50 is arranged between the outer
mast segment 111 and the middle mast segment 112 and between the
middle mast segment 112 and the inner mast segment 113. The
guide-roll arrangement 50 is thereby attached to one mast segment,
e.g. the upright 111.1 of the outer mast segment 111 such that its
roll 20 engages one of the opposing sidewalls 116, 117 of the track
114 in the adjacent upright 112.1 of the middle mast segment 112
and such that the sliding block 30 engages the bottom 115 of the
track 114.
[0031] FIG. 3c is a view from below of the lifting mast 110 of FIG.
2 and shows that the lifting mast 110 comprises further guide-roll
arrangements 50 arranged in inverted order with regards to the
guide-roll arrangements shown in FIG. 3a. Thus, a fifth and sixth
guide-roll arrangements 50 are attached to a respective upright
112.1, 112.2 of the middle mast segment 112 such that their
respective rolls 20 engages a track 114 on the adjacent uprights
111.1 and 111.2 of the outer mast segment 112. A seventh and eight
guide-roll arrangement 50 are attached to a respective upright
113.1 and 113.2 of the inner mast segment 113 such that their
respective rolls 20 engages an opposing sidewall 116, 117 of a
track 114 on an respective adjacent upright 112.1, 112.2 of the
middle mast segment 112.
[0032] FIG. 4 shows a guide-roll arrangement 50 according to the
present disclosure in detail. The guide-roll arrangement comprises
a roll pin 10, also denominated hub, which forms the center of the
guide-roll arrangement 50. The roll pin 10 is of rotational
symmetric cross-section, typically of circular cross-section, and
comprises opposing first and second ends 11, 12. Thus, the first
and the second ends 11, 12 faces away from each other. The roll pin
10 further comprises an envelope surface 21 which extends between
the first and second ends 11, 12. A roll 20 is supported on the
envelope surface 21 of the roll pin 10. The roll 20 is journaled by
ball bearings in the roll pin 10 such that it may rotate around the
roll pin (not shown in FIG. 4, but indicated in FIG. 3b). The first
end 11 of the roll-pin 10 comprises a recess 13 which extends from
the first end 11 towards the second end 12. The recess 13 is
thereby arranged in the centre of the roll pin 10. The recess 13
may be cylindrical and has a bottom 17 and a circumferential wall
18. A sliding member 30 is arranged in the recess 13 such that the
sliding surface 32 of the sliding member extends out of the recess
13. The sliding block 32 is typically a solid piece of e.g.
plastic, brass or graphite.
[0033] The second end 12 of the roll pin 10 is configured to be
attached to any of the mast segments 111, 112, 113 of the
lift-truck. Attachment of the second end 12 of the roll pin 10 to a
mast segment may be performed by welding.
[0034] The roll 20 of the guide-roll arrangement 50 may be made of
steel and is configured to engage one of the two opposing sidewalls
116, 117 of the elongated track 114 in the mast segment. The roll
is configured to engage, i.e. be in rolling contact with, one of
the opposing sidewalls 116, 117 or the track 114. The diameter of
the roll is therefore less than the distance between the two
opposing sidewalls 116, 117 of the track 114. For example, when the
roll engages one of the opposing sidewalls 116, 117 there is a
small gap between the roll and the other sidewall, for example of
2-5 mm. The sliding block 30 is configured such that the sliding
surface 32 may engage the bottom 115 of the track 114 (see FIG.
3b).
[0035] According to the disclosure, a support piece 40 is arranged
in the recess 13. The support piece 40 is arranged on the bottom 17
of the recess and comprises a contact surface 41 for supporting the
sliding element 30. The contact surface 41 is thereby facing away
from the bottom 17 of the recess. The sliding element 30 has a
contact surface 31 which is opposite the sliding surface 32. The
sliding element 30 is supported onto the support piece 40 such that
the contact surface 31 of the sliding element 30 is in contact with
the contact surface 41 of the support piece. The sliding element is
thereby freely movable, i.e. slidable, over the contact surface 41
of the support piece 40. Thus, there are no retaining elements or
forces between the contact surfaces 31, 41 of the support piece 40
and the sliding element 30.
[0036] Further according to the disclosure, one of the contact
surfaces 31, 41 of the sliding element 30 and the support element
40 is convex and the other of the contact surfaces 31, 41 is
concave. Thus, as shown in FIG. 5, the contact surface 41 of the
support element 40 is concave and the contact surface 31 of the
sliding element 30 is convex. However, it is possible to design the
support element 40 and the sliding element 30 such that the contact
surface 41 of the support element 40 is convex and the contact
surface 31 of the sliding element 30 is concave.
[0037] The advantage of freely supporting a sliding element 30
having a convex contact surface on concave support surface 41 of a
support element 40 is illustrated in FIGS. 5a and 5b.
[0038] In FIG. 5a the sliding element 30 is supported on the
support piece 40 and the sliding surface 32 of the sliding element
30 is engaging the bottom 115 of a track in outer mast segment 111
which is oriented in a substantially straight vertical direction.
The roll of the guide-roll element and the opposing sidewalls of
the track in the mast segment have been omitted for clarity.
[0039] In FIG. 5b, the outer mast segment 111 is subjected to an
external force F which displaces the mast segment 111 from the
straight vertical orientation of FIG. 5a. However, the convex
contact surface 31 of the sliding element 30 slides freely over the
concave contact surface 41 of the support piece 40 and the angular
orientation of the sliding element 30 follows thereby the angular
deviation of the outer mast segment 111. The sliding surface 32 of
the sliding element 30 therefore remains in full contact with the
bottom 115 of the track along the mast segment 111.
[0040] Returning to FIG. 4. Preferably, both the sliding element 30
and the support piece 40 are of circular cross-section and the
contact surfaces 31 and 41 of the respective sliding element 30 and
the support piece 40 are spherical. This is advantageous since the
mating spherical surface contact surfaces 31 and 41 allows for free
mobility of the sliding element 30 in all directions around its
centre axis. Preferably, the contact surfaces 31, 41 of the sliding
element 30 and the support piece 40 have the same diameter.
[0041] Preferably, the contact surface 31 of the sliding element 30
is convex and the contact surface 41 of the support piece 40 is
concave. This design allows for a stable movement of the contact
surface 31 of the sliding element 30 over the contact surface 41 of
the support piece 40 and also for improved self-centering of the
sliding element 30. The convex contact surface 31 of sliding
element 30 is typically achieved by a rounded end of the sliding
element 30. The concave contact surface 41 of the support piece 40
is typically provided by a depression in the support piece.
[0042] The sliding element 30 is preferably dimensioned such that
its outer diameter is less than the inner diameter of the recess
13. The diameter of the sliding element 30 and the recess 13 are
thereby dimensioned such that a predefined gap 22 is achieved
between the outer surface of the sliding element 30 and the
circumferential wall 18 of the recess 13. The purpose of the gap 22
is to control the degree of mobility of the sliding element and the
dimension of the gap 22 is thereby selected in dependency of the
construction of the lift-truck in question. For example, the gap
may be 1-2 mm.
[0043] To further control the degree of mobility of the sliding
element 30, an annular distance element 15 may be provided in the
circumferential wall 18 of the recess 13 for supporting the sliding
element 30 in radial direction Y. The annular distance element 15
is preferably of elastic material, such as rubber, and arranged in
an upper portion of the recess 13. The annular distance element 15
is preferably of circular cross-section and attached to the
circumferential wall 18 of recess 13 such that it contacts the
sliding element 30. For example, the annular distance element is
partially inserted into a groove 18 in the circumferential wall of
the recess 13. The annular distance element 15 thereby retains the
sliding element 30 within the recess 13 and ensures further that
the sliding element 30 does not press into the circumferential wall
18 of the recess 13 when it slides over the bottom of the track.
This could result in that the sliding element gets stuck in the
circumferential wall 18 of the recess 13.
[0044] The guide-roll arrangement 50 may further comprise a bore
14, such as a threaded bore, extending from the second end 12 of
the roll-pin 10 to the recess 13. A threaded adjustment element 16,
such as a threaded screw or bolt, may be arranged trough the
threaded bore and connected to the support piece 40 to provide the
possibility of moving the support piece 40 and thus the sliding
element 30 in axial direction of the roll-pin (This allows for
simple adjustment of the sliding element 30.
[0045] The radial direction Y and the axial direction X are
indicated by arrows in FIG. 4.
[0046] When in the present disclosure reference is made to a first
mast segment and a mast second segment this is made for
illustrative purpose only. It is appreciated that, for example, the
middle mast segment may be considered a first mast segment and that
the inner mast segment may be considered a second mast segment when
the inner mast segment moves relative the middle mast segment.
* * * * *